Suspension device for machines



Sept. 28, 1965 H. ELOY 3,208,705

SUSPENSION DEVICE FOR MACHINES Filed Sept. 4. 1963 2 Sheets-Sheet 1 wm/vro/e' Hen fL E/ 05 By m'ldno: JAB g TTO KNEHS Sept. 28, 1965 Filed Sept. 4. 1963 H. ELOY SUSPENSION DEVICE FOR MACHINES 2 Sheets-Sheet 2 lA/Vl-WIDE Henri E/o ATTOFLNEflS 3,208,705 Patented Sept. 28, 1965 3,208,705 SUSPENSION DEVICE FOR MACHINES Henri Eloy, 3 Grand Rte., Tihange, Belgium Filed Sept. 4, 1963, Ser. No. 306,572 Claims priority, application Belgium, Sept. 5, 1962, 622,160; July 30, 1963, 635,569 6 Claims. (Cl. 248130) The present invention concerns a suspension device for the tub of a washing and a drying machine, particularly of the type comprising a horizontally disposed tub and drum.

In these machines there is an extremely difiicult problem of balance when the machines are operating, either in the washing or the drying phase. The drum of the machine, rotating at a speed of about 50 revolutions per minute for washing and 500 revolutions per minute for drying is loaded, for example, with 1 to 6 kg. of laundry absorbing an average of three times its weight in water. During the washing phase the thus weighted laundry is repelled by centrifugal force against the internal wall of the drum and follows the latter in its rotation to a height where its weight exceeds the centrifugal force. The laundry then drops to the bottom of the drum, thus creating considerable imbalance. In addition the wet laundry is not distributed evenly over the internal wall of the drum. The stresses are even greater during the drying phase. The size of the imbalance can easily be demonstrated by an example.

Assuming that the drum is filled with kg. of laundry, absorbing three times its weight in water; this gives a load of 20 kg. If it is assumed that half the load is at maximum imbalance, i.e. kg., that it rotates at 400 revolutions per minute (a speed lower than the normal drying speed) and that the diameter of the drum is 450 mm., the following stress is obtained:

For a rotary speed of 500 revolutions per minute:

= 1,l00 kgs.

This is obviously a theoretical maximum, seeing that the imbalance decreases proportionally to the expulsion of water.

This problem has already formed the object of many tests and studies. One of the solutions proposed consists of suspending the tub and its drum from springs fixed at the other end to the body of the machine. This solution is hardly acceptable, in view of the forces transmitted to the body. Another, more rational solution was to pivot the horizontal tub along its lower generatrix, the tub being held in position by springs fixed to the body. Although this solution represents a certain advance, the fact remains that vibrations and stresses are still transmitted to the body, frequently causing the machine to be displaced when moved. This has led engineers to ballast the base of the machine, often with heavy Weights.

The present invention discloses a method for eliminating vibrations from the base of the body of a washing and drying machine.

The invention also discloses a device applying this method.

The method according to the invention substantially comprises absorbing the imbalances in the horizontal drum of a Washing machine by a pendulating movement and by vertical movements of the tub containing the drum; limiting the pendulating movement by the weight of the tub, drum, laundry and water contained therein and by twisting relatively resilient members; and finally, limiting the vertical movements by compressing and/or shearing resilient members.

The device according to the invention substantially comprises a frame on Which the horizontal tub is pivoted along its upper generatrix with the aid of resilient members, the frame being mounted on a base by resilient means.

A washing machine based on the method according to the invention has numerous advantages; for example, its operating safety is increased by the lessening of vibra tions, its stability makes it convenient to use, it is very easy to manufacture and more particularly to assemble, its weight is reduced and, finally, its body is entirely independent.

For the sake of clarity the invention is described below with reference to the accompanying drawings, in which:

FIGURE 1 is a perspective view of a washing machine according to the invention;

FIGURE 2 shows the machine illustrated in FIGURE 1 With the body removed;

FIGURE 3 is a diagram illustrating the method of absorbing the imbalance accordance to the invention;

FIGURE 4 is a diametrical section, in elevation, through a suspension member for the tub;

FIGURE 5 is an exploded perspective view of the characteristic members of the suspension shown in FIG- URE 4.

A washing machine of the type with a horizontal tub and drum according to the invention has a body 1 of any suitable shape, generally parallelepipedal, having a table 2 at the top, containing an orifice 3 closed by a cover 4. The rear part of the table 2 may carry a control head 5.

The body 1 is rigidly connected to a base 6 by screwing or bolting, the base comprising either one moulded piece or an assembly of sectional members.

The tub 7 containing the drum 8 is provided at the top with a rectangular projection 9, the upper end of the projection containing a circular orifice 10 lined with a rubber seal 11.

The method of eliminating the vibrations caused by the imbalance in the drum 8 comprises suspending the horizontal tub 7 containing the drum 8 substantially along its upper generatrix and absorbing the imbalances with oscillating movements, of variable amplitude 11, on the part of the tub 7, the drum 8 and the laundry 12 contained therein about the suspension shaft 13 and with generally vertical movements on the part of the tub 7 and its contents; limiting the oscillating movements with the weight of the tub 7, the drum 8, the laundry 12 and the water contained therein by twisting relatively resilient members arranged along the axis of oscillation 13, and finally, limiting the vertical movements by compressing resilient members.

In accordance with this method, the tub 7 is suspended substantially along its upper generatrix from two A-shaped struts 14 and 15 located on either side of the tub in planes perpendicular to the axis of the tub. According to one of the features of the invention the tub 7 is suspended from the struts 14, 15 as followings; at each of the upper generatrix of the tub 7 there is a tubular member 16 of which the axis is parallel to said generatrix, the members 16 being, for example, welded onto the external wall of the tub 7. The member joining the struts 14, 15 at the top is rigidly connected to a cylindrical member 17, one part of said upper member forming the base 18 of the cylinder 17 so as to provide a socket. The base 18 has an orifice 19 coaxial with the cylinder 17. The suspension device also comprises a bolt 20; a rubber coil 21 having an axial bore 22 of Which the diameter is at least equal to that of the bolt 20; a metal cup 23 having one flat face 24, a central bore 25 of a diameter at least equal to that of. the bolt 20, and having on its other face a collar 26, an annular rib 27, an annular recess 28 and a central conical hub 29; and a nut 30.

The feet of the A-shaped struts may be mounted on vibration-damping devices such as those shown diagrammatically at 31; these may, for example, be silent blocks.

However, it is preferable to use a damping device. The feet of the struts 14, 15 located on the same side of the diametrical vertical plane of the tub 7 are joined by a U-shaped section which cooperates with a similar section rigidly connected to the base of the machine, so as to form a case but without coming into contact with the section connected to the base. The case thus formed contains a coil of rubber which is subjected to radial tension by drawing together the two sections. The base may carry the accessories of the machine, such as the motor 32 which drives the drum 8 by means of the fiy' wheel 33 and belt 34. It should be noted that the drive belt 34 is virtually not subjected to any untimely stress, in view of the small sizes of the angle on.

However, in cases where the motor 32 stops when the drum is at drying speed, the sudden increase in the imbalance in the drum 8 brings a very marked increase in the size of the angle a, and the belt 34 then intervenes to limit the floundering movement of the tub 7.

The invention concerns the suspension device disclosed herein, in all its forms and applies to all types of washing and drying machines and to all machines where imbalances have to be partially or totally damped down.

The invention also covers these machines.

What I claim is:

1. A washing machine comprising, in combination, a drum-containing horizontal tub, a frame, a base, resilient means connected with said frame and pivotally suspending said tub above its center of gravity, and other resilient means fixing said frame upon said base, said frame comprising two struts substantially forming an A-shape and located opposite one another on either side of the planes containing the base of the tub.

2. A device according to claim 1, in which the resilient means adapted to produce compression, shearing and torsion and to suspend the tub comprises two devices substantially disposed at each end of the tub, each of the devices being made up of (a) a tubular member of which the axis is parallel to the generatrix integral with the tub, (b) a cylindrical member rigidly connected to the member joining the A-shaped strut at the top, the base of the cylindrical member being provided with a central orifice, (c) a coil of rubber having an axial bore and adapted to be housed in the tubular member and the cylindrical member,

the coil being compressed by tightening a nut engaging a bolt which is inserted through the orifice in a cylindrical member and through the axial bore in the coil with the aid of a metal washer.

3. A device according to claim 2, in which the metal washer has one fiat face, a central bore or diameter at least equal to that of the bolt, and, on its other face, going inwards from the periphery of that face, a collar, an annular rib, an annular recess, and a central conical hub.

4. A device according to claim 1, in which the struts forming an A-shape rest on said other resilient means.

5. A washing machine for cleaning fabrics, comprising a horizontal drum adapted to receive said fabrics, a tub enclosing said drum, a stationary base, a frame, damping means connecting said frame with said base, and two other damping means located on opposite sides of said tub and connecting said tub with said frame, each of said two other damping means comprising a bolt-shaped pin having a threaded portion, a resilient cylindrical member having an axial bore and mounted upon said pin, a cylinder rigidly connected with said frame and enclosing a portion of said resilient cylindrical member, another cylinder rigidly connected with said tub and enclosing another portion of said resilient cylindrical member, a metal washer slidably mounted upon said pin and a nut screwed upon the threaded portion of the pin; the two pins being in alinement and extending parallel to the axis of said drum and spaced vertically above the center of gravity of said drum, whereby said pins resiliently suspend said tub from opposite sides thereof.

6. A machine in accordance with claim 5, wherein said washer comprises an outer flat face engaging said nut and an inner face engaging said resilient cylindrical member and having an outer collar, an annular rib enclosed by said collar, an annular recess enclosed by said rib and a central conical hub.

References Cited by the Examiner UNITED STATES PATENTS 2,448,281 8/48 Saurer 2489 2,748,789 6/56 Nelson 13780 2,813,415 11/57 Clark 68-24 2,987,242 6/61 Mazzacane 230259 FOREIGN PATENTS 448,761 5/48 Canada.

CLAUDE A. LE ROY, Primary Examiner. 

5. A WASHING MACHINE FOR CLEANING FABRICS, COMPRISING A HORIZONTAL DRUM ADAPTED TO RECEIVE SAID FABRICS, A TUB ENCLOSING SAID DRUM, A STATIONARY BASE, A FRAME, DAMPING MEANS CONNECTING SAID FRAME WITH SAID BASE, AND TWO OTHER DAMPING MEANS LOCATED ON OPPOSITE SIDES OF SAID TUB AND CONNECTING SAID TUB WITH SAID FRAME, EACH OF SAID TWO OTHER DAMPING MEANS COMPRRISING A BOLT-SHAPED PIN HAVING A THREADED PORTION, A RESILIENT CYLINDRICAL MEMBER HAVING AN AXIAL BORE AND MOUNTED UPON SAID PIN, A CYCLINDER RIGIDLY CONNECTED WITH SAID FRAME AND ENCLOSING A PORTION OF SAID RESILIENT CYLINDRICAL MEMBERR, ANOTHER CYLINDER RIGIDLY CONNECTED WITH SAID TUB AND ENCLOSING ANOTHER PORTION OF SAID RESILIENT CYLINDRICAL MEMBER, A METAL WASHER SLIDABLY MOUNTED UPON SAID PIN AND A NUT SCREWED UPON THE THREADED PORTION OFF THE PIN; THE TWO PINS BEING IN ALINEMENT AND EXTENDING PARALLEL TO THE AXIS OF SAID DRUM AND SPACED VERTICALLY ABOVE THE CCENTER OF GRAVITY OF SAID DRUM, WHEREBY SAID PINS RESILIENTLY SUSPEND SAID TUB FROM OPPOSITE SIDES THEREOF. 